Permeation of oxygen/nitrogen in cobalt-chelated copoly(EDTA-MMA-BA) membranes

EDTA-MMA-BA copolymer was prepared by radical polymerization in aqueous sol ution. EDTA, which chelated cobalt ions (Co2+), at the chain end of copolym er was as an oxyphilic carrier Different cobalt ions contents of chelated c opolymer membranes were prepared and shown good oxygen permeability (P-O2=1 0x10(-9) cc(STP)cm/cm(2) s cmHg (100 barrer)) and highly permselectivity (a lpha(O-2/N-2)=10) of oxygen/nitrogen. The separation factor increased with the increasing of Co2+ contents in copolymer membranes. Both the permeation behaviors and the change of pressure were in good agreement with Petropoul os [J.H. Petropoulos, J. Polym. Sci. A2 8 (1970) 1797], Paul and Koros' [D. R. Paul, W.J. Koros, J. Polym. Sci.: Polym. Phys. Ed. 14 (1976) 675] modifi ed dual-mode absorption theory. The relationship between the oxygen or nitr ogen permeability and temperature follows the Arrhenius relation. The appar ent diffusion activation energies of oxygen and nitrogen were estimated to be 7.4-11.4 and 12 kcal/mol, respectively. (C) 2000 Elsevier Science B.V. A ll rights reserved.